Perfect Crystal Structure Research Articles

The Perfect Imperfections of Perovskite Oxide Catalysts in the Aspect of Defect Equilibria

ABX3 (X = O) perovskite oxides are an uprising class of alternative electrocatalysts in eminent technologies like electrocatalysis, photocatalysis, thermocatalysis, and energy storage. The perquisites of perovskite oxide catalysts encompass ordered atomic structure, structural/compositional extensibility, flexible electronic structure, lucrativeness, and so on. The ingenuity to precisely control and tune the inherent properties by reconstructing their crystal structure is particularly advantageous in electrocatalysis reactions like oxygen reduction and evolution reactions (ORR and OER). Incorporating multidimensional imperfections in the presumably perfect crystal structure of the perovskite catalysts is garnering booming attention among researchers. This concept can expertly influence the electronic structure and boost the reaction kinetics during electrocatalysis. Defects or imperfections are achieved by substituting A‐ and/or B‐sites with heteroatoms or by oxygen vacancies. Defect engineering points to a promising new direction in the development of perovskite oxide catalysts. This work surveys the recent progress in defect engineering and how it plays a vital role in their design, and application in electrocatalysis, mainly ORR/OER. The architecture, dimensionality, and the types of perovskite oxides based on their cations, crystal structures, and stoichiometries are surveyed for a comprehensive understanding. This review aims to provide an extensive outlook on oxide perovskite catalysts concerning structural defects.

Boron-incorporated IrO2-Ta2O5 coating as an efficient electrocatalyst for acidic oxygen evolution reaction

The Ir-based electrocatalysts for the acidic oxygen evolution reaction (OER) have demonstrated remarkable durability. Enhancing the Ir-based electrocatalytic activity still remains crucial owing to the scarcity of iridium. Here, a high-temperature sintering technique is employed to fabricate a boron (B)-incorporated IrO2-Ta2O5 coating with an almost perfect rutile-type crystal structure on a corrosion-resistant titanium substrate, ensuring exceptional stability for the acidic OER. The B-incorporated IrO2-Ta2O5 electrode fabricated in a mixed solution of 0.6 M H3BO3, exhibits an overpotential of 210 mV at a current density of 10 mA cm−2 and a lower Tafel slope of 34.2 mV dec−1 in a 0.5 M H2SO4 solution, which is far lower than the 272 mV overpotential and the 45.3 mV dec−1 of the IrO2-Ta2O5/Ti electrode. The electrode possesses a minimal potential increase even after undergoing continuous OER for 400 h at a high current density of 100 mA cm−2 in a 0.5 M H2SO4 solution. The incorporation of B species into IrO2-Ta2O5 effectively fine-tunes the electronic structure of Ir active sites, leading to a substantial enhancement of the intrinsic electrocatalytic activity. This study provides promising prospects for reducing the energy consumption of noble IrO2-based electrocatalysts in the practical application of electrochemical industry for the acidic OER.

Investigation of dislocation and twinning behavior in HMX under high-velocity impact employing molecular dynamics simulations.

Under the ReaxFF/lg force field, the multiscale shock technique (MSST) was employed to investigate the decomposition behavior of perfect, dislocated, and twinned octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) at a velocity of 11 km/s. This study aimed to analyze the changes in system temperature, bond formation and breaking, variations in the number of small molecules, and the number of clusters. The results indicated that the sensitivity of dislocated HMX was the lowest, while the sensitivity of twinned and perfect HMX was comparable. Comparing the formation and breaking of bonds in HMX during the shock process, it was found that the change in the number of bonds in dislocated HMX was similar to that in perfect HMX, whereas twinning accelerated the breaking of bonds. By analyzing the changes in small molecular fragments (CO, CO2, H, H2, H2O, N2, N2H, NH2, NO, NO2, and O) during the shock process of HMX, it was found that dislocation had a relatively minor effect on the small molecular fragments, while twinning promoted the generation of CO, H, NO, and O and accelerated the decomposition of NO. A comparison of the number, weight, and atomic ratio of clusters under perfect, dislocated, and twinned conditions revealed that under the influence of shock, the number of clusters initially increased sharply and then decreased slowly. Meanwhile, compared to the perfect and dislocated explosives, the number of clusters under the twinned structure was significantly fewer, indicating that the twinned structure could reduce cluster formation. The proportion of oxygen to carbon in the twinned HMX was lower than that in the perfect and dislocated explosives, possibly due to the higher content of small molecular fragment O in twinned HMX. Different structures of HMX crystals were constructed, including twinned defect structure (with a supercell containing 6458 atoms), dislocation defect structure (with a supercell containing 2352 atoms), and perfect structure (also with a supercell containing 2352 atoms). The modeling of defect crystal structures was carried out using the Atomsk software. For the twinned defect structure, we first constructed a mirror symmetric structure of the original configuration and then merged these two structures together. For the dislocation defect structure, we shifted a segment of the originally ordered perfect crystal structure by a certain distance using Atomsk. Before conducting the simulations, we performed geometric optimization of the models using the conjugate gradient (CG) algorithm and carried out 10 ps of NVT and NPT simulations to equilibrate the energy, temperature, and other parameters within the system. Finally, a 50-ps MSST impact simulation was performed using Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS).

Enhanced photocatalytic performance of SnS2 under visible light irradiation: strategies and future perspectives.

Tin(II) sulfide (SnS2) has emerged as a promising candidate for visible light photocatalytic materials. As a member of the transition metal dichalcogenides (TMDs) family, SnS2 features a band gap of approximately 2.20 eV and a layered structure, rendering it suitable for visible light activation with a high specific surface area. However, the application of SnS2 as a visible light photocatalyst still requires improvement, particularly in addressing the high recombination of electrons and holes, as well as the poor selectivity inherent in its perfect crystal structure. Therefore, ongoing research focuses on strategies to enhance the photocatalytic performance of SnS2. In this comprehensive review, we analyze recent advances and promising strategies for improving the photocatalytic performance of SnS2. Various successful approaches have been reported, including controlling the reactive facets of SnS2, inducing defects in the crystal structure, manipulating morphologies, depositing noble metals, and forming heterostructures. We provide a detailed understanding of these phenomena and the preparation techniques involved, as well as future considerations for exploring new science in SnS2 photocatalysis and optimizing performance.

О геохимической зональности Верхне-Алиинского месторождения золота в Забайкалье (Россия)

The relevance of the study lies in the need to have objective geochemical data to assess the erosion section level of newly discovered manifestations of ore deposits. One of the examples, used to solve this problem, is the results of the mineralogy and geochemistry study of the Verkhnealiinsky gold deposit in Transbaikalia. The purpose of the study is to determine the zonality in the distribution of minerals, gold and associated chemical elements in the deposit space and to evaluate them as criteria for ore zoning. The object of the study is the Verkhnealinsky gold deposit. The subject of the research is the spatial distribution of minerals and chemical elements in the gold ore zones of the deposit. The methodology consists in diagnostics, determination of the chemical elements content and the establishment of regularities in their spatial distribution using modern methods of analysis, namely, electron microscopy, assay analysis and ICP MS, determination of the degree of the crystal structure perfection. The results of the study are as follows: the content of gold and associated chemical elements in the three most industrially important ore-bearing zones of the Western, Latitudinal and Eastern zones, which differ in the depth of formation, have been determined. The least deep Eastern zone is characterized by the intensive development of zinc, lead, antimony, and arsenic minerals and, accordingly, their maximum content in its upper part. For the deepest Western zone, the maximum development of pyrrhotite, chalcopyrite, and cobalt has been revealed, and it is shown that the cobalt-nickel ratio is an important criterion for assessing the level of erosion cut. An important criterion of depth is also the degree of the crystalline structure perfection of vein quartz, which depends both on the crystallization rate, which is determined by the depth from the day surface during the formation of the deposit, and on the amount of isomorphic impurities in it. It is also shown that one of the important criteria for the level of erosion section is the content of rubidium in veined quartz and arsenic in pyrite.

Crystal structure of ZnO nanocrystals synthesized by the spray pyrolysis method

The paper discusses the issues related to the influence of technological conditions of synthesis by ultrasonic spray pyrolysis on the size and lattice parameters of ZnO:Mn nanocrystals. It is found that, depending on the concentration of zinc nitrate in the base solution from 5% to 10%, the synthesized nanocrystals have sizes ranging from 36÷40 nm for small solution droplets and 51÷55 nm for large droplets, respectively. Based on the X-ray diffraction data, it is found that the nanocrystals of small sizes have a more perfect crystal structure with a small number of intrinsic defects compared to the nanocrystals of larger sizes.

Effect of pretreatment synergistics on Shenfu low-rank coal pyrolysis in molten metal

The two key factors that significantly impact coal pyrolysis are its structural composition and the medium in which it is carried out. In this study, effects of acid pretreatment (AP), hydrothermal pretreatment (HTP), and acid-hydrothermal synergistic pretreatment (AP-HTP) on Shenfu Low-rank coal (SF) structure were investigated. In molten metals (MM), the distribution and composition of coal pyrolysis products were investigated to evaluate the impact of pretreatment synergistics. The results showed that changing the structure of the coal had a significant effect on the pyrolysis behavior. The molten metal stimulated the pyrolytic conversion of the coal. Pyrolysis in molten metal with AP-HTP synergistic pretreatment coal (SF-AH/MM) increased the tar yield and reduced the water yield. The tar of SF-AH/MM increased aromatic and phenolic compounds, while decreased the aliphatic and oxygen compounds. The H2 increased by 19.48 % and carbon oxides decreased for the gas of SF-AH/MM. Moreover, the char of SF-AH/MM enriched the aromatic structure and the content of the perfect graphite crystal structure, while reduced the degree of graphite lattice defects. The pretreatment synergistics affected the structure of coal and the molten metals enhanced the pyrolysis process, the distribution of products was optimized. Pyrolysis of synergistic pretreatment coal in molten metals is promising to enhance the tar yield, the H2 yield and improved the quality of the char.

Investigation of Defect Formation in Silicon Doped with Silver and Gadolinium Impurities by Raman Scattering Spectroscopy

Silicon doped with gadolinium and silver impurities were studied using a Renishaw InVia Raman spectrometer. Registration and identification of both crystalline and amorphous phase components in the samples was carried out. Some changes are observed in the Raman spectra of gadolinium-doped silicon samples compared to the initial sample. It has been experimentally found that an increase in the silver impurity concentration in gadolinium-doped silicon leads to a smoothing of the Raman spectrum, which indicates the formation of a more perfect crystal structure.

Synthesis of silver nanoparticles formed by Chaerophyllum macrospermum and Eremurus spectabilis biomaterial and investigation of photovoltaic parameters by adding silicon phthalocyanine

Silver nanoparticles (AgNPs) were obtained by green synthesis using Chaerophyllum macrospermum (CM) and Eremurus spectabilis (ES). These particles were characterized by TEM, XRD, IR, UV, mass, and NMR spectra. TEM images show that the mean particle size of CM-AgNPs was 30 nm and the diameter of ES-AgNPs was 14.2 nm. XRD measurements showed that CM-AgNPs were 30.85 nm and ES-AgNPs 18.80 nm in a perfect face-centered cubic crystal structure. CM-AgNP showed maximum absorption at 453 nm and ES-AgNP at 455 nm; AgNPs exhibited a strong surface plasmon resonance (SPR) and played a role in stabilization. A silicon phthalocyanine compound was synthesized and characterized. The photovoltaic properties of the axial phthalocyanine compound with and without doping of Chaerophyllum macrospermum and Eremurus spectabilis silver nanoparticles were investigated. Better dye-sensitive solar cells were formed by doping silver nanoparticles to phthalocyanine compounds with an increase in the percentage of energy conversion efficiency by 0.26 with ESAgNP doping and 0.76 with CMAgNP doping.

The Effect of Reducing Agent for Synthesizing Palladium Nanoparticle on Carbon Nanotube Support and Its Superior Catalytic Activity towards Methanol Oxidation Reaction

In this report, we have synthesized carbon nanotube supported palladium nanoparticles (CNT-Pd) by using different reducing agents such as sodium borohydride (SBH), hydrazine monohydrate (HY) and ascorbic acid (AA) for the methanol oxidation reaction (MOR) in alkaline media. The elemental and morphological properties of all catalysts are verified by HRTEM, XPS, and XRD. From the HRTEM images, it is found that CNT-Pd reduced by sodium borohydride CNT-Pd (SBH) exhibited a narrow size distribution of Pd nanoparticles (PdNPs) with an average size of 3.15 nm. The role of the reducing agents (SBH, HY, and AA) is investigated by applying them as anode catalysts for the methanol oxidation reaction (MOR) and it is found that the reducing agent remarkably affected the electrochemical activities. CNT-Pd (SBH) catalysts show the superior catalytic activity and durability towards MOR among all catalysts, which may be due to the Pd NPs in CNT-Pd (SBH) having a perfect crystal structure with a narrow size distribution.

Specific absorption rate in quasispherical and elongated aggregates of magnetite nanoparticles: Experimental characterization and numerical simulation

Assemblies of magnetite nanoparticles created by the ultrasonic mechanocavitation in a viscous liquid have been obtained for use in magnetic hyperthermia. The magnetite nanoparticles inherit the perfect crystal structure of the original coarse-grained magnetite powder, with characteristic sizes of 0.2–8 μm, and have a high saturation magnetization, Ms = 92 emu/g, close to the value of pure magnetite. Measurements of the specific absorption rate (SAR) of assemblies in an alternating (ac) magnetic field showed a significant dependence of SAR on the nanoparticle concentration, as well as on the shape of particle macroaggregates. A 4-fold increase in the SAR of elongated clusters of particles oriented parallel to the action of ac magnetic field was found in comparison with an assembly of quasi-spherical clusters. In addition a sharp dependence of the SAR of an assembly of elongated clusters on the ac magnetic field direction with respect to the cluster orientation axis was revealed. The results obtained are in qualitative agreement with the results of numerical simulation of dense clusters of magnetic nanoparticles based on the solution of the stochastic Landau-Lifshitz equation.

In situ Ti assisted graphitization approach for the preparation of graphite foam with light weight and high thermal conductivity.

The state-of-the-art graphite foams (GFs) are afflicted by large bulk density and low thermal conductivity, restricting their practical application. To alleviate the above problem, herein, an issue-oriented scheme, i.e., an in situ titanium (Ti) assisted catalytic graphitization strategy was proposed by using AR mesophase pitch (ARMP) as a precursor. In a typical preparation process, the mixture of Ti and ARMP underwent a pressurized foam, carbonization, and graphitization procedure successively to obtain GFs. The results showed that the Ti content played an important role in the development of the graphitic microcrystal structure due to the catalytic graphitization of Ti. According to the XRD analysis and molecular dynamics (MD) simulation, we confirmed that Ti promoted graphitization mainly by the generation of TiC during the high-temperature graphitization. The GFs obtained with 11 wt% Ti exhibited the most perfect graphitic crystal structure, with the highest graphitization degree. Thanks to the improved graphitization degree, the thermal conductivity of GFs increased with the added amount of Ti increasing from 0 to 11 wt%. The highest thermal conductivity of 60.8 W m-1 K-1 and the low bulk density of 0.36 g cm-3 could be achieved when the addition amount of Ti was 11 wt%. Meanwhile, apart from the optimization of thermal conductivity and bulk density, the compressive strength was also enhanced as the amount of Ti increased from 0 to 15 wt%. Our work provided a facile and scalable approach to preparing GFs with low density and high thermal conductivity.

Revealing the effect of Nb5+ on the electrochemical performance of nickel-rich layered LiNi0.83Co0.11Mn0.06O2 oxide cathode for lithium-ion batteries

The layered Nb5+-doped LiNi0.83Co0.11Mn0.06O2 (NCM) oxide cathode materials are successfully synthesized through introducing Nb2O5 into the precursor Ni0.83Co0.11Mn0.06(OH)2 during the lithiation process. The results refined by GSAS software present that the Nb5+-doped samples possess the perfect crystal structure with broader Li+ diffusion pathways. Moreover, the morphology characterized by scanning electron microscope displays the compact secondary particles packed by smaller primary particles under the effect of Nb5+. The excellent electrochemical properties are also acquired from the Nb5+-doped samples, in which the optimal rate performance and cycling stability are performed for NCM-1.0 when up to 1.0 mol % of Nb2O5 (based on the precursor) is added. Benefited from the introduction of Nb5+, the cell assembled with the NCM-1.0 electrode retains higher capacity retention of 86.6 % at 1.0 C and 25 °C, and 71.7 % at 1.0 C and 60 °C after 200cycles. Moreover, it also delivers higher discharge specific capacity of 154.6 mAh g−1 at 5.0 C. Therefore, the Nb5+-doping strategy may open an effective route for optimizing nickel-rich oxide cathode materials, which is worth popularizing for the enhancement of the electrochemical performance of nickel-rich cathodes for lithium-ion batteries.

Ni-decorated Sn(HPO4)2 anchored on reduced graphene oxide boosting initial Coulombic efficiency and cyclic stability for lithium-ion batteries

Layered Sn(HPO4)2 with perfect crystal structure and large interlayer spacing shows considerable lithium storage capacity worthy of study, but its intrinsic poor conductivity and low initial Coulombic efficiency (ICE) as anode material for lithium-ion batteries need to be enhanced. Herein, Sn(HPO4)2 is first decorated by Ni nanoparticles through electroless plating, then anchored on reduced graphene oxide (rGO). The well-conductive Ni nanoparticles distributed uniformly on the surface of Sn(HPO4)2 can help to inhibit the irreversible sites on the surface and reduce electrochemical kinetic impedance, thus the Ni/Sn(HPO4)2 anode exhibits improved ICE and capacity retention ratios, which are almost twice that of bare Sn(HPO4)2 anode. Meanwhile, the conductive network formed by rGO in rGO/Ni/Sn(HPO4)2 composite not only weakens the electrochemical reaction polarization, but also keeps the electrode structure stable and provides extra lithium storage sites, so rGO/Ni/Sn(HPO4)2 anode delivers higher ICE of 60.29%, superior cyclic stability of 79.7% capacity retention after 120 cycles with at 0.1 A g−1.

Selective dopant induced spin flipping and complex ferro–antiferromagnetic interaction in Nd based cuprate francisite

A study of Nd based cuprate francisite (NdCufr) is fascinating due to the presence of competing magnetic interactions in this geometrically frustrated layered compound, and Ni doping helps in tailoring these interactions. Here, Ni doped NdCufr is synthesized to compare its magnetic properties with pristine and Co doped NdCufr. Structural (x-ray diffraction, XRD), electronic (x-ray absorption near edge spectroscopy, XANES, and extended x-ray absorption fine structure, EXAFS), and magnetic (temperature dependent magnetization, M–T; field dependent magnetization, M–B) properties are investigated. The XRD, XANES, and EXAFS measurement data show a perfect crystal structure and confirm the merit of doping. A comprehensive comparison for examining the role of Co and Ni in modulation with ferromagnetic–antiferromagnetic interaction strength is presented. A crucial interplay of intra- and interlayer couplings, along with f–d interaction, effectively describes the tuning of Neel temperature (TN) and M–B. Detailed processes of field induced metamagnetic transition around the spin-flip ordering field (BSF), which is equal to that of the critical field (BC) and doping induced ferromagnetism, are addressed considering the relative spin orientations of magnetic elements and energy level splitting schemes, respectively. It is found that the studied compound is magnetically superior to the compared compounds.

Well-defined Co-N-C catalyst based on ZIF-67 in mixed solvents with low amount of ligands for efficient oxygen reduction reaction

Non-precious metal nitrogen-carbon composites (M-N-C) derived from ZIFs are an excellent non-precious metal catalyst for use in energy conversion and storage devices such as fuel cells and metal-air batteries. Herein ZIF-67 precursor with good dispersion, perfect crystal structure and size of below 270 nm was synthesized by consuming low amount of 2-methylimidazole ligand using a mixture of ethanol (EA) and methanol (MT) as the reaction medium. Compared with the traditional method of reducing the size of ZIF-67 by increasing the amount of ligands in methanol, this method avoids the waste of raw materials and saves the cost. The Co-N-C-MT/EA catalysts derived from ZIF-67 exhibits good ORR activity in alkaline media (0.1 M KOH) with a half-wave potential of 0.81 V vs RHE. After 5000 cycles, the initial potential and half-wave potential basically remain no change, showing excellent long-term stability. And remarkable methanol resistance is also displayed comparing with commercial Pt/C. The present experimental result shows that the improved synthesis method of ZIF-67 precursors has far-reaching implications for the field of catalyst research.

Cobalt-free nickel-rich layered LiNi0.9Al0.1-xZrxO2 cathode for high energy density and stable lithium-ion batteries

BackgroundTo meet the challenges of limited resources and the toxicity of cobalt, cobalt freed Ni-rich layered cathode materials for high energy density power batteries have become a hot spot. However, the poor stability upon cycling hindered their applications. MethodsA layered Zr-introduced Ni-Al based Co-free cathode material LiNi0.9Al0.1-xZrxO2 (NAZ) is designed and synthesized with a sol-gel method. Significant findingsThe prepared Co-free cathode material exhibits perfect crystal structure stability and electrochemical performance, which are attributed to the incorporation of Zr4+ with high-valence and strong Zr-O bond energy. The obtained LiNi0.9Al0.08Zr0.02O2 (NAZ-2) shows a first discharge capacity of 177.5 mAh g−1 at 1 C, and maintains about 92.45 % after 100 charge / discharge cycles. It also displays a high specific capacity of 160 mAh g−1 at 5 C. Furthermore, compared to the pure sample, LiNi0.9Al0.08Zr0.02O2 (NAZ-2) shows a lower charge transfer impedance of 57.90 Ω and larger diffusion coefficient of lithium ions of 5.70217 × 10−9 cm2 S−1, which is conducive to the migration of Li+ and the inhibiting of the polarization.

Effect of Crystallization on Shape Memory Effect of Poly(lactic Acid).

The opportunity for the preparation of high-performance shape memory materials was brought about by the excellent mechanical properties of poly(lactic acid) (PLA). As the effect of crystallization on shape memory was still unclear, this brings constraints to the high-performance design of PLA. The PLA plates with different aggregation structure were prepared by three kinds of molding methods in this paper. The PLA plates were pre-stretched with a series of different strains above glass transition temperature (i.e., 70 °C). The recovery stress and ratio of the material were measured above stretching temperature (i.e., 80 °C). Prolonging of annealing time resulted in more perfect crystal structure and higher crystallinity. The crystal region acted as network nodes in shape memory PLA, and crystal region structure determined the shape memory performance. Based on the experimental results, the structural evolution of network nodes in shape memory PLA was established.

Enhancing quality of CsPbIBr<sub>2</sub> inorganic perovskite via cellulose acetate addition for high-performance perovskite solar cells

<sec>CsPbIBr<sub>2</sub> perovskite has been considered as a promising candidate for the light-harvesting material of perovskite solar cells (PSCs) due to its acceptable band gap and high stability. Nevertheless, the efficiency of CsPbIBr<sub>2</sub>-based PSC still lags behind that of its homologs and is far away from the theoretical value. This can be attributed to the poor quality of CsPbIBr<sub>2</sub> perovskite film. Therefore, it is highly desirable to improve the quality of CsPbIBr<sub>2</sub> perovskite film for enhancing the photovoltaic performance of CsPbIBr<sub>2</sub> PSCs. In this work, cellulose acetate (CA) is used as a polymer additive that is introduced into CsPbIBr<sub>2</sub> precursor solution for improving the quality of CsPbIBr<sub>2</sub> perovskite film via controlling crystallization process. The interaction between the C=O group of CA and Pb<sup>2+</sup> in the precursor solution and the enhanced viscosity of precursor solution induced by CA addition reduce the crystallization rate of CsPbIBr<sub>2</sub> perovskite. As a result, a compact CsPbIBr<sub>2</sub> perovskite film with high crystallinity, large grain size, and low density of defect is prepared. The remarkably improved quality of CsPbIBr<sub>2</sub> perovskite film upon CA addition can be attributed to the relatively slow crystallization rate. The slow crystallization rate allows the perovskite film to have enough time to form perfect perovskite crystal structure with large-size crystal grain and low density of defects. Furthermore, the oxygen functional groups of CA can passivate the undercoordinated Pb<sup>2+</sup>, which effectively suppresses the defects and traps induced by Pb<sup>2+</sup> in CsPbIBr<sub>2</sub> perovskite film.</sec> <sec>The stability of CsPbIBr<sub>2</sub> perovskite film is also greatly improved by CA addition. The added CA does not participate into the CsPbIBr<sub>2</sub> perovskite crystal but distributes at the grain boundaries and, or, interfaces area and forms a moisture barrier around perovskite grains, which obviously enhances the stability of CsPbIBr<sub>2</sub> perovskite film in the ambient air.</sec> <sec>The carbon-based CsPbIBr<sub>2</sub> perovskite solar cells with a configuration of FTO/TiO<sub>2</sub>/perovskite film/ carbon are fabricated by using the carbon layer as both the hole-transport layer and the back electrode. Under the illumination of 100 mW/cm<sup>2</sup>, the PSC based on CA-CsPbIBr<sub>2</sub> perovskite film delivers a high conversion efficiency of 7.52%, which is increased by 40% compared with the efficiency of the device based on the pure CsPbIBr<sub>2</sub> perovskite film. In addition, the PSC based on CA-CsPbIBr<sub>2</sub> perovskite film shows a hysteresis index (HI) of 7%, while the device based on pure CsPbIBr<sub>2</sub> film displays a higher HI of 22%. This result demonstrates that the CA addition can effectively suppress the hysteresis effect of inorganic PSCs. The stability of the PSC based on CA-CsPbIBr<sub>2</sub> perovskite film is investigated by tracking the variation of the efficiency with time in the ambient condition. The fabricated PSCs without any encapsulation are stored in the air. The photovoltaic performance is measured once a day. The efficiency of the PSC based on CA-CsPbIBr<sub>2</sub> perovskite remains more than 90% of its initial value after being stored in the air for 800 h, showing an excellent long-term stability. Therefore, this work provides a facile and effective method of improving the quality of CsPbIBr<sub>2</sub> perovskite films, which is expected to be helpful in developing high-efficiency and stable carbon-based inorganic PSCs.</sec>

RADIATION STIMULATION OF THE CATALYTIC ACTIVITY OF ZIRCONIUM DIOXIDE NANOPARTICLES DURING THE CONVERSION OF HYDROCARBONS

The comparison of the catalytic activity of the initial and activated by bremsstrahlung -radiation on a high-current electron accelerator of zirconium dioxide nanoparticles on the nature of the conversion of ethanol. The used -activation parameters contributed to the formation of a more perfect crystal structure of ZrO2 nanoparticles. It was shown that when using -activated ZrO2 nanoparticles as a catalyst, the yield of hydrocarbon products during the conversion of ethanol was several times higher than the yield of the same products in the case of using the initial ZrO2 nanoparticles. The mechanism of such a conversion of ethanol can be associated with the synergism of large ionization losses of Auger electrons and the effect of highly reactive products involved in heterogeneous catalysis.